The project of this research is to describe in detail the movement of cilia and the relationship of the movement of cilia to the movement of water, mucus and particles. This will be done by cinephotomicrography and by flash photomicrography using Nomarski interference-contrast microscopy, Emphasis will be placed on the study of ciliated epithelium in which the movement of a mucus blanket is the primary function and will involve study of several animals including the bivalve gill and the pharynx and respiratory tract of frog, chick and rat. Physiological experimentation involving nerve stimulation and treatment with various neurotransmitters and local mediators will be carried out to determine to what extent the ciliary activity is under organismic control. One eventual objective is the accumulation of enough information so that ciliated cells in metazoa may be classified according to their responses and control mechanisms. The way in which the beating of individual cilia contributes to the formation of a metachronal wave will be studied by scanning electron microscopy of rapidly fixed waves. The proximity of endogenous mediator substances and nerves will be determined by fluorescence histochemistry and by transmission electron microscopy of tissue stained for cholinesterase.